Automated fiber placement machines are nowadays widely used to manufacture parts, components, and structures from composite materials. These systems typically comprise a fiber placement head carried out in space by a multi-axis positioner, with the head responsible for laying up carbon fiber composite onto a stationary mold.
The materials used in automated fiber placement heads are typically composed of unidirectional carbon fibers pre-impregnated into a resin that appears as tapes, or thin strips, commonly known as “tows.”
Each head is usually capable of laying and compacting a plurality of tows of a determined dimension (such as ⅛″, ⅜″, ½″, etc.) arranged side-by-side to form a “ply” or “course” over and onto a tool. The head usually has all means to lay-up the tows/tape automatically such as a compaction roller, means to individually cut or add each tow whenever required, as well as means to heat up the tows/tape and/or the substrate zone to ensure sufficient tack for tow/tape adhesion. The head is also automatically fed by an integrated tow magazine (referred to as a “creel”) which supplies the tow/tape in an organized array and with a correct tension.
In order to achieve flexibility, usually a CNC controlled positioner is capable of selectively and automatically picking up a desired head—creel assembly from a magazine and under instructions provided by suitable control means is capable of following a desired multiple-pass lay-up path onto a stationary or rotating mold duly anchored to ground.
One of the most common positioner arrangements adopted is a gantry-type of machine travelling above a single working envelope located within the gantry travelling columns and extending longitudinally along the X-axis of the machine.
One restricted portion of the positioner working area is usually used by the positioner to access to the heads' magazine. Such a configuration, while recognized as allowing for the manufacture of parts within the working envelope, is limited to that single envelope. As a result, as parts are loaded and unloaded from the working envelope, the machine is idle. Unfortunately, this machine down time has led to inefficiencies, especially considering the growing demand for the rapid production of composite parts. As such, there is a need in the art for a fiber placement system with greater efficiency.
The invention provides such a fiber placement system and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.